Specific interactions between protein and nucleic acids are the fundamental events governing the expression, replication and packaging of all chromosomal elements. This proposal describes studies of the molecular aspects of such interactions in several RNA-containing viruses including RNA tumor viruses, vesicular stomatitis virus and reovirus, as well as studies of DNA-protein interactions governing the initiation of replication in plasmids and yeast. Both biochemical and biological approaches to these studies will be employed including protein and nucleic acid sequencing, affinity chromatography, DNA cloning, and immunological analyses employing both standard antisera and hybridoma to all secreted monoclonal antibodies. Information gained from these studies will have fundamental implications for numerous virus-related disease processes, cell transformation and oncogenesis.